Supramolecular Sequential Assembly of Polymer Thin Films Based on Dimeric, Dendrimeric, and Polymeric Schiff-Base Ligands and Metal Ions

Abstract

New metal-Schiff-base coordination polymer films were prepared using multiple sequential adsorption of metal ions and salen-based ligand molecules. As the ligands, bis-bidentate 5,5'-methylene-bis(N-methylsalicylidenamine) (MBSA), tetra-bidentate N,N',N' ',N' ''-tetrasalicylidene-polyamidoamine (TSPA), and multi-bidentate poly(N-salicylidenevinylamine) (PSVA) were used. The metal ions were Cu(II), Zn(II), Fe(II), Fe(III), and Ce(IV). The resulting films are deeply colored due to the formation of coordinative bonds between the metal ions and the salen groups. Our study indicates that film formation becomes progressively easier, if the number of salen groups per ligand molecule increases. While Cu(II), Ni(II), Fe, and Ce(IV) are well suited for complex formation, Zn(II) is less suited. Possible structures of the polymers are discussed. Cyclic voltammetric studies of the films are also presented.

Formation of polymeric chain assemblies of transition metal complexes with a multidentate Schiff-base

“…The development of self-assembled polymeric species based on transition metal compounds and multidentate ligands has been the subject of extensive research due to their potential applications in supramolecular [1,2] and environmental chemistry and medicine. One approach in supramolecular chemistry has been to develop coordination polymers with unique properties.…”

Coordination of carbonyl oxygen in the complexes of polymeric N-crotonyl-2-hydroxyphenylazomethine

“…Transition metal polymeric complexes are of current interest due to their potential applications in supramolecular [1,2] and environmental chemistry and medicine. One approach in the field of supramolecular chemistry has been to investigate the use of polymeric ligands to develop complexes with metal centres that have unusual coordination and new properties.…”

Covalent Layer‐by‐Layer Assembly Using Reactive Polymers

“…In addition, while conventional LbL processes for the assembly of PEMs are generally restricted to the use of aqueous solutions (owing to the limited solubility of many polyelectrolytes in solvents other than water), many materials useful for covalent LbL assembly are compatible with the use of organic solvents, including aprotic and less polar solvents, which can expand the range of substrates and interfaces on which films can be deposited. Finally, a particularly useful feature of these covalent approaches is that they often result in polymer multilayers containing residual, unreacted functional groups (either on the surface or in the interior of a film; e.g., Figure 15.1c) that can be exploited postfabrication, and under mild conditions, to covalently attach and/or create patterns of other functionalities using a wide range [112][113][114][115][116][117][118][119][120][121][122][123] of different chemical and biological agents ( Figure 15.1d). Although it is certainly not impossible to chemically functionalize or pattern the surfaces of conventional PEMs, the combination of increased film stability and chemical reactivity afforded by these reactive approaches can greatly facilitate postfabrication modification and, in general, opens the door to new opportunities for the design of functional surfaces and interfaces.…”

“…In addition, several recent reports also demonstrate the utility of metal-ligand interactions as a means of promoting LbL assembly. For example, interactions of various metal complexes with polymers bearing amine [112], carboxylic acid [113,114], salicylidene [115,116], and pyridine-containing [117][118][119][120][121] and palladium pincer-type [122,123] groups have been used to assemble metal complex crosslinked polymer films under a variety of different conditions. The metal-ligand bonds formed in these examples should be regarded as coordinate bonds rather than as covalent bonds.…”